An efficient and general method for the synthesis of 2,9-disubstituted 8-hydroxyadenines, which are expected to have various biological activities, was realized. 5-Amino-4-cyano-2-hydroxyimidazoles (1) were prepared from aminomalononitrile and isocyanates as key intermediates. The condensation of 1a with amidines, imidates, guanidine, urea and thioureas afforded 8-hydroxyadenines (2–6) possessing various substituents at the 2-position. Furthermore, selective alkylation of 2-amino- and 2-hydroxyadenines (4 and 6) successively proceeded to give the corresponding 2-alkylamino- and 2-alkoxyadenines (5 and 7), respectively. 2-Alkylthioadenines (15) were prepared by an analogous reaction of 1a with benzoyl isothiocyanate and subsequent S-alkylation. The imidazoles 1 are most useful intermediates for the synthesis of 8-hydroxyadenine derivatives.
一种高效且通用的方法被实现,用于合成预期具有多种
生物活性的2,9-二取代的8-羟基
腺苷。5-
氨基-4-
氰基-2-羟基
咪唑(1)是从
氨基
丙腈和
异氰酸酯作为关键中间体制备的。将1a与
氨基
脲、
咪唑、
胍、
尿素和
硫脲缩合,得到在2位具有各种取代基的8-羟基
腺苷(2–6)。此外,对2-
氨基和2-羟基
腺苷(4和6)进行选择性烷基化,顺利实现,分别得到相应的2-烷基
氨基和2-烷氧
腺苷(5和7)。2-烷基
硫腺苷(15)是通过1a与苯甲酰异
硫氰酸酯的类似反应以及随后S-烷基化制备的。
咪唑类化合物1是合成8-羟基
腺苷衍
生物最有用的中间体。